Here’s another chance to play geographical detective! These four images from the Multi-angle Imaging SpectroRadiometer (MISR) cover the same geographic area but were acquired on four different dates. Each image was acquired by MISR’s vertical-viewing (nadir) camera and encompasses an area measuring 257 kilometers x 195 kilometers. North is toward the top.
This mystery concerns a small island located near the western edge of the observed area. In the top two images, the island presents an obstacle to the westerly winds, and wake patterns in the cloud layers are visible downstream of the island’s location. In the lower left image, the island is visible within a relatively clear area of open ocean. In the lower right image, the island is partially obscured by cumulus clouds, and a spiral cloud pattern associated with an atmospheric depression is visible in the southeast quadrant.
The Terra satellite, with MISR aboard, flies in a polar orbit and daylight images such as these are acquired as the spacecraft flies from north to south. Terra’s orbit is “sun-synchronous”, and when the satellite crosses the daylight equator the local time beneath the spacecraft is approximately 10:30 a.m. The four images shown here were processed identically, and relative variations in brightness between the different views have been preserved.
Using any reference materials you like, please answer the following 5 questions:
- The images contain multiple clues that can be used to determine whether
the observed area is situated in the northern or southern hemisphere. Name the
hemisphere and describe at least two clues you used to establish your answer.
(Clues should not make use of knowledge of the island’s identity.)
- Three of the following four statements about the island’s environment are
true. Which one is false?
A. Glaciers cover most of the island, and vegetation is limited to lichens and mosses.
B. The island is of volcanic origin and located at the intersection of oceanic ridges.
C. A colony of Atlantic puffins makes the island its home.
D. The highest peak rises more than 750 meters above sea level.
- Three of the following four statements about the history of the island are
true. Which one is false?
A. Sovereignty over the island was transferred from one country to another sometime between 1918 and 1932.
B. Steep cliffs make the island difficult to access, and despite many attempts the first landing did not take place until the 1850’s.
C. In the 19th century, a whaling/sealing expedition christened the island with the name of a city located in their native country.
D. The earliest documented discovery of the island was by an 18th century French explorer, and the island is currently named after this individual.
- All five of the following events took place, but only four occurred during
the second half of the 20th century. Which one did not occur in this time
A. The island and adjacent waters were designated a nature reserve.
B. A weather station was established on the island, providing automated temperature and pressure data.
C. A nuclear bomb test occurred within 3000 kilometers of the island.
D. An abandoned boat of unknown origin was discovered on the island. E. The island’s seals were declared to be protected species.
- What is the name of the island and to which country does it belong?
E-mail your answers, name (initials are acceptable if you prefer), and your hometown by Tuesday, July 16, 2002, to email@example.com.
Answers will be published on the MISR web site ( http://www-misr.jpl.nasa.gov) in conjunction with the next weekly image release. The names and home towns of respondents who answer all questions correctly by the deadline will also be published in the order responses were received. The first 3 people on this list who are not affiliated with NASA, JPL, or MISR and who did not win a prize in the last quiz will be sent a print of the image.
A new “Where on Earth...?” mystery appears as the MISR “image of the week” approximately once per month. A new image of the week is released every Wednesday at noon Pacific time on the MISR home page. The image also appears on the Atmospheric Sciences Data Center home page, http://eosweb.larc.nasa.gov/, though usually with a several-hour delay.
Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.